Java™ Runtime Environment (JRE) 5.0 Update 21 (for older systems Win 98/ME)
The J2SE Runtime Environment (JRE) allows end-users to run Java applications.

The full internal version number for this update release is 1.5.0_21-b01 (where "b" means "build"). The external version number is 5.0u21.
Changes in 1.5.0_21 - Release Notes

Additional Supported System Configurations
As of this update, support has been added for the following system configurations:
  • Windows Vista SP, Server 2008 SP2
Refer to the Supported System Configurations page.

Downloads:
http://java.sun.com/javase/downloads/index_jdk5.jsp


J2SE 5.0 is in its Java Technology End of Life (EOL) transition period.
The EOL transition period began April 8th, 2008 and will complete October 30th, 2009, when J2SE 5.0 will have reached its End of Service Life (EOSL). Migrate to the latest Java SE release JRE 6 Update